Originally Posted by biker1 (Post 2276251)

It doesn't really work that way for many systems. Systems with an ECM motor in the air handler will continue to produce essentially the same CFM as the filter becomes loaded. ECM motors are programmed to provide a specific amount of air flow. Of course, this is up to a point. A filter can become so loaded that the ECM motor cannot compensate. If you have a 4" media filter and no outstanding sources of "stuff" in the air, annual filter changes should be fine.

Originally Posted by Maker (Post 2276382)

Flow controlled closed loop motor controls have nothing to do with the amount of stuff captured by either filter type. It only alters the blower speed to compensate for a plugged filter. That does not make the filter material any different.

Sounds like that reply is implying that the paper filter will capture more stuff (even with the same MERV rating), and the blower motor speed will need to be increased.

Still looking for a real answer to my question. Why will the paper filter become more restrictive to the washable one, given that both are MERV 8 and both are the same physical construction.

Originally Posted by retiredguy123 (Post 2275893)

While potentially true, I have had no issues using the MERV 11 filters. These filters reduce both dust and noise in the house. No problem with air flow. I recommend them over the MERV 8 filters.